我已经在以下文章中实现了相同的方法，如果您需要进一步的帮助，请Plz告诉我，我将提供代码

http://rchern.wordpress.com/2008/05/11/updatepanel-backforward-browser-
navigation/

首先，您必须启用ScriptManager历史记录EnableHistory =“ true”
在此示例中，我们将维护gridview分页，当用户浏览器后退按钮时，您必须在首次加载页面后添加历史记录点。

private void AddHistoryPoint(String key, String value, String tile)
{
    ScriptManager scm = ScriptManager.GetCurrent(this.Page);
    if ((scm.IsInAsyncPostBack == true) && (scm.IsNavigating != true))
    {
        if (pageState == null)
        {
           NameValueCollection pageState = new NameValueCollection();
        }
        if (pageState[key] != null)
        {
            pageState[key] = value;
        }
        else
        {
            pageState.Add(key, value);
        }
        scm.AddHistoryPoint(pageState, tile);
    }
}

protected void grid_PageIndexChanged1(object sender, EventArgs e)
{
    AddHistoryPoint("pi", grdProject.PageIndex.ToString(), "Page Index- " + (grdProject.PageIndex + 1).ToString());
}

在这里，您必须处理ScriptManager导航事件

     protected void ScriptManager1_Navigate(object sender, System.Web.UI.HistoryEventArgs e)
{
    if (e.State != null)
    {
        if (e.State["pi"] != null)
        {
            grid.PageIndex = Convert.ToInt32(e.State["pi"]);
        }
    }
}